files: Generalize fd restore, introduce file_desc

The struct replaces bare list_head on all of the _info-s we've
introduced recently.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

files.c

@@ -36,11 +36,23 @@ int prepare_shared_fdinfo(void)
 	return 0;
 }
 
+void file_desc_add(struct file_desc *d)
+{
+	INIT_LIST_HEAD(&d->fd_info_head);
+}
+
+struct fdinfo_list_entry *file_master(struct file_desc *d)
+{
+	BUG_ON(list_empty(&d->fd_info_head));
+	return list_first_entry(&d->fd_info_head,
+			struct fdinfo_list_entry, list);
+}
+
 struct reg_file_info {
 	struct reg_file_entry rfe;
 	char *path;
 	struct list_head list;
-	struct list_head fd_head;
+	struct file_desc d;
 };
 
 #define REG_FILES_HSIZE	32
@@ -57,7 +69,7 @@ void show_saved_files(void)
 			struct fdinfo_list_entry *le;
 
 			pr_info(" `- ID %x\n", rfi->rfe.id);
-			list_for_each_entry(le, &rfi->fd_head, list)
+			list_for_each_entry(le, &rfi->d.fd_info_head, list)
 				pr_info("   `- FD %d pid %d\n", le->fd, le->pid);
 		}
 }
@@ -74,24 +86,24 @@ static struct reg_file_info *find_reg_file(int id)
 	return NULL;
 }
 
-static struct list_head *find_reg_fd(int id)
+static struct file_desc *find_reg_desc(int id)
 {
 	struct reg_file_info *rfi;
 
 	rfi = find_reg_file(id);
-	return &rfi->fd_head;
+	return &rfi->d;
 }
 
-static struct list_head *find_fi_list(struct fdinfo_entry *fe)
+static struct file_desc *find_file_desc(struct fdinfo_entry *fe)
 {
 	if (fe->type == FDINFO_REG)
-		return find_reg_fd(fe->id);
+		return find_reg_desc(fe->id);
 	if (fe->type == FDINFO_INETSK)
-		return find_inetsk_fd(fe->id);
+		return find_inetsk_desc(fe->id);
 	if (fe->type == FDINFO_PIPE)
-		return find_pipe_fd(fe->id);
+		return find_pipe_desc(fe->id);
 	if (fe->type == FDINFO_UNIXSK)
-		return find_unixsk_fd(fe->id);
+		return find_unixsk_desc(fe->id);
 
 	BUG_ON(1);
 	return NULL;
@@ -135,7 +147,7 @@ int collect_reg_files(void)
 		rfi->path[len] = '\0';
 
 		pr_info("Collected [%s] ID %x\n", rfi->path, rfi->rfe.id);
-		INIT_LIST_HEAD(&rfi->fd_head);
+		file_desc_add(&rfi->d);
 		chain = rfi->rfe.id % REG_FILES_HSIZE;
 		list_add_tail(&rfi->list, &reg_files[chain]);
 	}
@@ -153,7 +165,7 @@ static int collect_fd(int pid, struct fdinfo_entry *e)
 {
 	int i;
 	struct fdinfo_list_entry *l, *le = &fdinfo_list[nr_fdinfo_list];
-	struct list_head *fi_list;
+	struct file_desc *fdesc;
 
 	pr_info("Collect fdinfo pid=%d fd=%ld id=%16x\n",
 		pid, e->addr, e->id);
@@ -168,13 +180,13 @@ static int collect_fd(int pid, struct fdinfo_entry *e)
 	le->fd = e->addr;
 	futex_init(&le->real_pid);
 
-	fi_list = find_fi_list(e);
-	if (fi_list == NULL) {
+	fdesc = find_file_desc(e);
+	if (fdesc == NULL) {
 		pr_err("No file for fd %d id %d\n", (int)e->addr, e->id);
 		return -1;
 	}
 
-	list_for_each_entry(l, fi_list, list)
+	list_for_each_entry(l, &fdesc->fd_info_head, list)
 		if (l->pid > le->pid)
 			break;
 
@@ -214,12 +226,12 @@ int prepare_fd_pid(int pid)
 	return ret;
 }
 
-static int open_fe_fd(struct list_head *l)
+static int open_fe_fd(struct file_desc *d)
 {
 	struct reg_file_info *rfi;
 	int tmp;
 
-	rfi = container_of(l, struct reg_file_info, fd_head);
+	rfi = container_of(d, struct reg_file_info, d);
 
 	tmp = open(rfi->path, rfi->rfe.flags);
 	if (tmp < 0) {
@@ -242,7 +254,7 @@ static int find_open_fe_fd(struct fdinfo_entry *fe)
 		return -1;
 	}
 
-	return open_fe_fd(&rfi->fd_head);
+	return open_fe_fd(&rfi->d);
 }
 
 static int restore_cwd(struct fdinfo_entry *fe, int fd)
@@ -294,29 +306,29 @@ void transport_name_gen(struct sockaddr_un *addr, int *len,
 	*addr->sun_path = '\0';
 }
 
-static int should_open_transport(struct fdinfo_entry *fe, struct list_head *fd_list)
+static int should_open_transport(struct fdinfo_entry *fe, struct file_desc *fd)
 {
 	if (fe->type == FDINFO_PIPE)
-		return pipe_should_open_transport(fe, fd_list);
+		return pipe_should_open_transport(fe, fd);
 	if (fe->type == FDINFO_UNIXSK)
-		return unixsk_should_open_transport(fe, fd_list);
+		return unixsk_should_open_transport(fe, fd);
 
 	return 0;
 }
 
-static int open_transport_fd(int pid, struct fdinfo_entry *fe, struct list_head *fd_list)
+static int open_transport_fd(int pid, struct fdinfo_entry *fe, struct file_desc *d)
 {
 	struct fdinfo_list_entry *fle;
 	struct sockaddr_un saddr;
 	int sock;
 	int ret, sun_len;
 
-	fle = file_master(fd_list);
+	fle = file_master(d);
 
 	if (fle->pid == pid) {
 		if (fle->fd == fe->addr) {
 			/* file master */
-			if (!should_open_transport(fe, fd_list))
+			if (!should_open_transport(fe, d))
 				return 0;
 		} else
 			return 0;
@@ -326,11 +338,11 @@ static int open_transport_fd(int pid, struct fdinfo_entry *fe, struct list_head
 
 	pr_info("\t%d: Create transport fd for %lx\n", pid, fe->addr);
 
-	list_for_each_entry(fle, fd_list, list)
+	list_for_each_entry(fle, &d->fd_info_head, list)
 		if ((fle->pid == pid) && (fle->fd == fe->addr))
 			break;
 
-	BUG_ON(fd_list == &fle->list);
+	BUG_ON(&d->fd_info_head == &fle->list);
 
 	sock = socket(PF_UNIX, SOCK_DGRAM, 0);
 	if (sock < 0) {
@@ -354,29 +366,29 @@ static int open_transport_fd(int pid, struct fdinfo_entry *fe, struct list_head
 }
 
 static int open_fd(int pid, struct fdinfo_entry *fe,
-		struct list_head *fd_list, int *fdinfo_fd)
+		struct file_desc *d, int *fdinfo_fd)
 {
 	int tmp;
 	int serv, sock;
 	struct sockaddr_un saddr;
 	struct fdinfo_list_entry *fle;
 
-	fle = file_master(fd_list);
+	fle = file_master(d);
 	if ((fle->pid != pid) || (fe->addr != fle->fd))
 		return 0;
 
 	switch (fe->type) {
 	case FDINFO_REG:
-		tmp = open_fe_fd(fd_list);
+		tmp = open_fe_fd(d);
 		break;
 	case FDINFO_INETSK:
-		tmp = open_inet_sk(fd_list);
+		tmp = open_inet_sk(d);
 		break;
 	case FDINFO_PIPE:
-		tmp = open_pipe(fd_list);
+		tmp = open_pipe(d);
 		break;
 	case FDINFO_UNIXSK:
-		tmp = open_unix_sk(fd_list);
+		tmp = open_unix_sk(d);
 		break;
 	default:
 		tmp = -1;
@@ -397,7 +409,7 @@ static int open_fd(int pid, struct fdinfo_entry *fe,
 
 	pr_info("\t%d: Create fd for %lx\n", pid, fe->addr);
 
-	list_for_each_entry(fle, fd_list, list) {
+	list_for_each_entry(fle, &d->fd_info_head, list) {
 		int len;
 
 		if (pid == fle->pid) {
@@ -437,12 +449,12 @@ out:
 	return 0;
 }
 
-static int receive_fd(int pid, struct fdinfo_entry *fe, struct list_head *fd_list)
+static int receive_fd(int pid, struct fdinfo_entry *fe, struct file_desc *d)
 {
 	int tmp;
 	struct fdinfo_list_entry *fle;
 
-	fle = file_master(fd_list);
+	fle = file_master(d);
 
 	if (fle->pid == pid)
 		return 0;
@@ -490,9 +502,9 @@ static int open_fdinfo(int pid, struct fdinfo_entry *fe, int *fdinfo_fd, int sta
 {
 	u32 mag;
 	int ret = 0;
-	struct list_head *fi_list;
+	struct file_desc *fdesc;
 
-	fi_list = find_fi_list(fe);
+	fdesc = find_file_desc(fe);
 	if (move_img_fd(fdinfo_fd, (int)fe->addr))
 		return -1;
 
@@ -502,13 +514,13 @@ static int open_fdinfo(int pid, struct fdinfo_entry *fe, int *fdinfo_fd, int sta
 
 	switch (state) {
 	case FD_STATE_PREP:
-		ret = open_transport_fd(pid, fe, fi_list);
+		ret = open_transport_fd(pid, fe, fdesc);
 		break;
 	case FD_STATE_CREATE:
-		ret = open_fd(pid, fe, fi_list, fdinfo_fd);
+		ret = open_fd(pid, fe, fdesc, fdinfo_fd);
 		break;
 	case FD_STATE_RECV:
-		ret = receive_fd(pid, fe, fi_list);
+		ret = receive_fd(pid, fe, fdesc);
 		break;
 	}
 

include/files.h

@@ -39,12 +39,15 @@ struct fdinfo_list_entry {
 	futex_t			real_pid;
 };
 
+struct file_desc {
+	struct list_head fd_info_head;
+};
+
+extern void file_desc_add(struct file_desc *d);
+extern struct fdinfo_list_entry *file_master(struct file_desc *d);
+
 extern void transport_name_gen(struct sockaddr_un *addr,
 				int *len, int pid, long fd);
-static inline struct fdinfo_list_entry *file_master(struct list_head *fd_list)
-{
-	return list_first_entry(fd_list, struct fdinfo_list_entry, list);
-}
 
 void show_saved_files(void);
 extern int collect_reg_files(void);
@@ -55,11 +58,12 @@ extern int get_filemap_fd(int pid, struct vma_entry *vma_entry);
 
 extern int self_exe_fd;
 
+struct file_desc;
 extern int collect_pipes(void);
 extern void mark_pipe_master(void);
-extern int open_pipe(struct list_head *l);
-struct list_head *find_pipe_fd(int id);
+extern int open_pipe(struct file_desc *);
+struct file_desc *find_pipe_desc(int id);
 extern int pipe_should_open_transport(struct fdinfo_entry *fe,
-					struct list_head *fd_list);
+		struct file_desc *d);
 
 #endif /* FILES_H_ */

include/sockets.h

@@ -11,18 +11,19 @@ extern int dump_socket(struct fd_parms *p, int lfd,
 		const struct cr_fdset *cr_fdset);
 
 struct fdinfo_list_entry;
-struct list_head *find_inetsk_fd(int id);
-struct list_head *find_unixsk_fd(int id);
+struct file_desc;
+struct file_desc *find_inetsk_desc(int id);
+struct file_desc *find_unixsk_desc(int id);
 struct fdinfo_entry;
 extern int unixsk_should_open_transport(struct fdinfo_entry *,
-		struct list_head *);
+		struct file_desc *);
 extern int collect_sockets(void);
 extern int collect_inet_sockets(void);
 extern int collect_unix_sockets(void);
 extern int resolve_unix_peers(void);
 extern int run_unix_connections(void);
-extern int open_inet_sk(struct list_head *);
-extern int open_unix_sk(struct list_head *);
+extern int open_inet_sk(struct file_desc *);
+extern int open_unix_sk(struct file_desc *);
 struct cr_options;
 extern void show_unixsk(int fd, struct cr_options *);
 extern void show_inetsk(int fd, struct cr_options *);

pipes.c

@@ -19,7 +19,7 @@ struct pipe_info {
 	struct list_head pipe_list;	/* all pipe_info with the same pipe_id
 					 * This is pure circular list whiout head */
 	struct list_head list;		/* list head for fdinfo_list_entry-s */
-	struct list_head fd_head;
+	struct file_desc d;
 	int create;
 	int bytes;
 	off_t off;
@@ -37,12 +37,12 @@ static struct pipe_info *find_pipe(int id)
 	return NULL;
 }
 
-struct list_head *find_pipe_fd(int id)
+struct file_desc *find_pipe_desc(int id)
 {
 	struct pipe_info *pi;
 
 	pi = find_pipe(id);
-	return &pi->fd_head;
+	return &pi->d;
 }
 
 int collect_pipes(void)
@@ -68,7 +68,7 @@ int collect_pipes(void)
 
 		pr_info("Collected pipe entry ID %x PIPE ID %x\n",
 					pi->pe.id, pi->pe.pipe_id);
-		INIT_LIST_HEAD(&pi->fd_head);
+		file_desc_add(&pi->d);
 
 		list_for_each_entry(tmp, &pipes, list)
 			if (pi->pe.pipe_id == tmp->pe.pipe_id)
@@ -93,7 +93,7 @@ static void show_saved_pipe_fds(struct pipe_info *pi)
 	struct fdinfo_list_entry *fle;
 
 	pr_info("  `- ID %p %xpn", pi, pi->pe.id);
-	list_for_each_entry(fle, &pi->fd_head, list)
+	list_for_each_entry(fle, &pi->d.fd_info_head, list)
 		pr_info("   `- FD %d pid %d\n", fle->fd, fle->pid);
 }
 
@@ -155,7 +155,7 @@ void mark_pipe_master()
 		pr_info(" `- PIPE ID %x\n", pi->pe.pipe_id);
 		show_saved_pipe_fds(pi);
 
-		fle = file_master(&pi->fd_head);
+		fle = file_master(&pi->d);
 		p = pi;
 		fd = fle->fd;
 		pid = fle->pid;
@@ -163,7 +163,7 @@ void mark_pipe_master()
 		list_for_each_entry(pic, &pi->pipe_list, pipe_list) {
 			list_move(&pic->list, &head);
 
-			fle = file_master(&p->fd_head);
+			fle = file_master(&p->d);
 			if (fle->pid < pid ||
 			    (pid == fle->pid && fle->fd < fd)) {
 				p = pic;
@@ -183,10 +183,11 @@ void mark_pipe_master()
 }
 
 int pipe_should_open_transport(struct fdinfo_entry *fe,
-				struct list_head *fd_list)
+		struct file_desc *d)
 {
-	struct pipe_info *pi = container_of(fd_list, struct pipe_info, fd_head);
-
+	struct pipe_info *pi;
+	
+	pi = container_of(d, struct pipe_info, d);
 	return !pi->create;
 }
 
@@ -196,7 +197,7 @@ static int recv_pipe_fd(struct pipe_info *pi)
 	char path[PATH_MAX];
 	int tmp, fd;
 
-	fle = file_master(&pi->fd_head);
+	fle = file_master(&pi->d);
 	fd = fle->fd;
 
 	pr_info("\tWaiting fd for %d\n", fd);
@@ -264,7 +265,7 @@ err:
 	return ret;
 }
 
-int open_pipe(struct list_head *l)
+int open_pipe(struct file_desc *d)
 {
 	unsigned long time = 1000;
 	struct pipe_info *pi, *pc, *p;
@@ -273,7 +274,7 @@ int open_pipe(struct list_head *l)
 	int sock;
 	int create;
 
-	pi = container_of(l, struct pipe_info, fd_head);
+	pi = container_of(d, struct pipe_info, d);
 
 	pr_info("\tCreating pipe pipe_id=%x id=%x\n", pi->pe.pipe_id, pi->pe.id);
 
@@ -298,8 +299,7 @@ int open_pipe(struct list_head *l)
 		struct sockaddr_un saddr;
 		struct fdinfo_list_entry *fle;
 
-		BUG_ON(list_empty(&p->fd_head));
-		fle = file_master(&p->fd_head);
+		fle = file_master(&p->d);
 
 		pr_info("\t\tWait fdinfo pid=%d fd=%d\n", fle->pid, fle->fd);
 		futex_wait_while(&fle->real_pid, 0);

sockets.c

@@ -790,7 +790,7 @@ struct unix_sk_info {
 	char *name;
 	unsigned flags;
 	struct unix_sk_info *peer;
-	struct list_head fd_head;
+	struct file_desc d;
 };
 
 #define USK_PAIR_MASTER		0x1
@@ -808,12 +808,12 @@ static struct unix_sk_info *find_unix_sk(int id)
 	return NULL;
 }
 
-struct list_head *find_unixsk_fd(int id)
+struct file_desc *find_unixsk_desc(int id)
 {
 	struct unix_sk_info *ui;
 
 	ui = find_unix_sk(id);
-	return &ui->fd_head;
+	return &ui->d;
 }
 
 struct sk_packet {
@@ -902,7 +902,7 @@ static int restore_socket_queue(int fd, unsigned int peer_id)
 struct inet_sk_info {
 	struct inet_sk_entry ie;
 	struct list_head list;
-	struct list_head fd_head;
+	struct file_desc d;
 };
 
 #define INET_SK_HSIZE	32
@@ -920,12 +920,12 @@ static struct inet_sk_info *find_inet_sk(int id)
 	return NULL;
 }
 
-struct list_head *find_inetsk_fd(int id)
+struct file_desc *find_inetsk_desc(int id)
 {
 	struct inet_sk_info *ii;
 
 	ii = find_inet_sk(id);
-	return &ii->fd_head;
+	return &ii->d;
 }
 
 int collect_inet_sockets(void)
@@ -950,7 +950,7 @@ int collect_inet_sockets(void)
 		if (ret <= 0)
 			break;
 
-		INIT_LIST_HEAD(&ii->fd_head);
+		file_desc_add(&ii->d);
 		chain = ii->ie.id % INET_SK_HSIZE;
 		list_add_tail(&ii->list, &inet_sockets[chain]);
 	}
@@ -962,13 +962,13 @@ int collect_inet_sockets(void)
 	return 0;
 }
 
-int open_inet_sk(struct list_head *l)
+int open_inet_sk(struct file_desc *d)
 {
 	int sk;
 	struct sockaddr_in addr;
 	struct inet_sk_info *ii;
 
-	ii = container_of(l, struct inet_sk_info, fd_head);
+	ii = container_of(d, struct inet_sk_info, d);
 
 	show_one_inet_img("Restore", &ii->ie);
 
@@ -1219,7 +1219,7 @@ int run_unix_connections(void)
 
 		pr_info("\tConnect %x to %x\n", ui->ue.id, peer->ue.id);
 
-		fle = file_master(&ui->fd_head);
+		fle = file_master(&ui->d);
 
 		memset(&addr, 0, sizeof(addr));
 		addr.sun_family = AF_UNIX;
@@ -1275,11 +1275,11 @@ done:
 }
 
 int unixsk_should_open_transport(struct fdinfo_entry *fe,
-				struct list_head *fd_list)
+				struct file_desc *d)
 {
 	struct unix_sk_info *ui;
 
-	ui = container_of(fd_list, struct unix_sk_info, fd_head);
+	ui = container_of(d, struct unix_sk_info, d);
 	return ui->flags & USK_PAIR_SLAVE;
 }
 
@@ -1313,7 +1313,7 @@ static int open_unixsk_pair_master(struct unix_sk_info *ui)
 		return -1;
 	}
 
-	fle = file_master(&peer->fd_head);
+	fle = file_master(&peer->d);
 	futex_wait_while(&fle->real_pid, 0);
 
 	pr_info("\tSending pair to %d's %d\n",
@@ -1337,7 +1337,7 @@ static int open_unixsk_pair_slave(struct unix_sk_info *ui)
 	struct fdinfo_list_entry *fle;
 	int sk;
 
-	fle = file_master(&ui->fd_head);
+	fle = file_master(&ui->d);
 
 	pr_info("Opening pair slave (id %x peer %x) on %d\n",
 			ui->ue.id, ui->ue.peer, fle->fd);
@@ -1386,11 +1386,11 @@ static int open_unixsk_standalone(struct unix_sk_info *ui)
 	return sk;
 }
 
-int open_unix_sk(struct list_head *l)
+int open_unix_sk(struct file_desc *d)
 {
 	struct unix_sk_info *ui;
 
-	ui = container_of(l, struct unix_sk_info, fd_head);
+	ui = container_of(d, struct unix_sk_info, d);
 	if (ui->flags & USK_PAIR_MASTER)
 		return open_unixsk_pair_master(ui);
 	else if (ui->flags & USK_PAIR_SLAVE)
@@ -1454,7 +1454,7 @@ int collect_unix_sockets(void)
 
 		ui->peer = NULL;
 		ui->flags = 0;
-		INIT_LIST_HEAD(&ui->fd_head);
+		file_desc_add(&ui->d);
 		pr_info(" `- Got %u peer %u\n", ui->ue.id, ui->ue.peer);
 		list_add_tail(&ui->list, &unix_sockets);
 	}
@@ -1497,10 +1497,9 @@ int resolve_unix_peers(void)
 		 * the one in pipes.c and makes sure tasks wait for each other
 		 * in pids sorting order (ascending).
 		 */
-		BUG_ON(list_empty(&ui->fd_head) || list_empty(&peer->fd_head));
 
-		fle = file_master(&ui->fd_head);
-		fle_peer = file_master(&peer->fd_head);
+		fle = file_master(&ui->d);
+		fle_peer = file_master(&peer->d);
 
 		if ((fle->pid < fle_peer->pid) ||
 				(fle->pid == fle_peer->pid &&
@@ -1519,7 +1518,7 @@ int resolve_unix_peers(void)
 
 		pr_info("\t%x -> %x (%x) flags %x\n", ui->ue.id, ui->ue.peer,
 				ui->peer ? ui->peer->ue.id : 0, ui->flags);
-		list_for_each_entry(fle, &ui->fd_head, list)
+		list_for_each_entry(fle, &ui->d.fd_info_head, list)
 			pr_info("\t\tfd %d in pid %d\n",
 					fle->fd, fle->pid);